A recent article (Migrating to Page Controllers) does an excellent job of combining theory with some concrete examples and immediate benefits. The article provides a simple technique for factoring the controller out of the view processing when writing PHP code. Although not necessary for everything, architecture along this direction can really pay off for web apps. Many of the PHP apps that I’ve looked at recently have stand alone pages, and that can make them pretty hard to transform. The trend to move all the processing up to the front of the page helps out quite a bit. Programmers now tend to setup their objects and variables all in one block at the top, and then include the display pages with minimal markup to output the dynamic bits. Unfortunately error display still gets stuck into the logic pretty often. It certainly helps out quite a bit to have all the processing done up front, and that’s half way to the page controller model. The final bit is the refactoring to pull the different views out of the logic and defining a consistent scheme for passing the display info to them. I like the way the description comes off, very practical and tailored towards those who have to refactor their apps to make them look like this.
During the Q&A; at the Niklaus Wirth talk last night someone mentioned formal methods from the Hoare school of work. Such as Hoare Logic. In particular they were asking why the work there had fallen out of favor, and wasn’t used more widely. Which got me thinking about the cost of axiomatic proof of computer systems. Which got me thinking about my background in computer security.
The success of Pascal came many years after it was done, due to the availability of microcomputers. Now there were lots of people available to program who didn’t have to unlearn Fortran. It was driven forward by Borland making the compiler available for only 50 dollars, when other compilers cost thousands. This made a mass market for Pascal.
Here’s some quick notes from the talk that Niklaus Wirth gave at the Computer History Museum on Oct 20th. The topic was “How I Became Interested In Computer Languages”.
Two sets of notes from the New Geography workshop put on by the Institute For The Future
Niklaus Wirth is speaking at the Computer History Museum in Mountain View on the topic “How I Became Interested in Programming Languages”. Wirth is one of those names that pops up over and over again in computer science, like Knuth. I’ve never heard him speak before, and I’m certainly not going to pass up the opportunity to. An RSVP is required, so visit that link and fill out the registration info if you’re planning to go.
There’s an SDForum panel presentation tomorrow about Music and Metadata:
Brian Cantoni has a good writeup of a talk about Semantic XHTML given by Kevin Marks and Tantek Celik. The slides are available online as well. There’s some good stuff in there. Lately I’ve been working a bunch with the idea of mixing in additional information with web content. The ideas become much more interesting with the read-write-web in my opinion. There’s an elegant layered model for moving user content around evolving. The APIs that started out with blogging, like MetaWeblog and Atom, provide a transport mechanism. Semantic XHTML can provide the structure for those posts to turn a blog post into something more, like an address book update or a calendar event. And those two realms can remain distinct. A standard blog post without semantic information remains a valid post, using Semantic XHTML in some cases doesn’t preclude using standard HTML in others. For instance the metadata for a micro-content system could be passed as semantic XHTML in a blog post. Systems used to tend to either require metadata or not allow it at all. New systems, like the del.icio.us bookmarking system, allow for optional metadata and don’t enforce any restrictions on how the info is used.
Gnomedex was fantastic. Lots of people to talk to, and I thought the panel discussions were interesting even if others found some fault with them. Being at the conf you hear about a bunch of stuff that it’s hard to find your way to if you weren’t there to hear the off the cuff comments or pick up the links from IRC (I really should have logged the channel… oops). So here’s a bunch of stuff, some from the previous page I had and some new stuff:
I’ve had some great conversations over at Gnomedex so far. Here is a by-no-means complete set of links to people I didn’t know before, but I had interesting conversations with. Now I’m going to be reading their stuff.
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